Clean up mime package.

pkg/mime/lib/src/mime_type.dart

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 library mime.mime_type;
 
 import 'default_extension_map.dart';
 import 'magic_number.dart';
 
 final MimeTypeResolver _globalResolver = new MimeTypeResolver();
 
 /**
  * The maximum number of bytes needed, to match all default magic-numbers.
  */
-// NOTE: this is not formatted AS_A_CONST to avoid a breaking change
-const int defaultMagicNumbersMaxLength = 12;
+int get defaultMagicNumbersMaxLength => _globalResolver.magicNumbersMaxLength;
 
 /**
  * Extract the extension from [path] and use that for MIME-type lookup, using
  * the default extension map.
  *
  * If no matching MIME-type was found, `null` is returned.
  *
  * If [headerBytes] is present, a match for known magic-numbers will be
  * performed first. This allows the correct mime-type to be found, even though
  * a file have been saved using the wrong file-name extension. If less than
@@ skipping 15 matching lines @@
   /**
    * Create a new empty [MimeTypeResolver].
    */
   MimeTypeResolver.empty() : _useDefault = false, _magicNumbersMaxLength = 0;
 
   /**
    * Create a new [MimeTypeResolver] containing the default scope.
    */
   MimeTypeResolver() :
       _useDefault = true,
-      _magicNumbersMaxLength = defaultMagicNumbersMaxLength;
+      _magicNumbersMaxLength = DEFAULT_MAGIC_NUMBERS_MAX_LENGTH;
 
   /**
    * Get the maximum number of bytes required to match all magic numbers, when
    * performing [lookup] with headerBytes present.
    */
   int get magicNumbersMaxLength => _magicNumbersMaxLength;
 
   /**
    * Extract the extension from [path] and use that for MIME-type lookup.
    *
@@ skipping 12 matching lines @@
       if (result != null) return result;
       if (_useDefault) {
         result = _matchMagic(headerBytes, DEFAULT_MAGIC_NUMBERS);
         if (result != null) return result;
       }
     }
     var ext = _ext(path);
     result = _extensionMap[ext];
     if (result != null) return result;
     if (_useDefault) {
-      result = DEFAULT_EXTENSION_MAP[ext];
+      result = defaultExtensionMap[ext];
       if (result != null) return result;
     }
     return null;
   }
 
   /**
    * Add a new MIME-type mapping to the [MimeTypeResolver]. If the [extension]
    * is already present in the [MimeTypeResolver], it'll be overwritten.
    */
   void addExtension(String extension, String mimeType) {
@@ skipping 24 matching lines @@
     return null;
   }
 
   static String _ext(String path) {
     int index = path.lastIndexOf('.');
     if (index < 0 || index + 1 >= path.length) return path;
     return path.substring(index + 1).toLowerCase();
   }
 }